Ford certainly DID make a 1.4 Zetec-SE engine
it was fitted to the Mark 4 and some Mk 5 fiestas so THEORETICALLY it should fit into the Ka pretty well
although I'd check the clearance of the throttle bodies
It's a dohc, multipoint FI engine producing [according to Ford] 89 bhp, god knows what that one would be producing tho? 140 bhp?
IN FACT, I sold a fezzy a couple weeks ago with the engine in [hence the knowledge
] and found a piccy of the engine:
This one had a K+N and some exhaust on it and sounded nice, was pretty lively too